Method of coating



June 6, 1933. G. M K. BROWN METHOD OF COATING 2 Sheets-Sheet 1 Filed Feb. 13, 1930 June 6, 1933. G. MacK. BROWN METHOD OF COATING Fi-led Feb. 15,1930 2 Sheets-Sheet .2

IN VENTR n w 0 v! B Nu b 9 T 0 e 6 Patented June 1933 enolwn IAcK EN ZIE Brown, or ronnon. mz'omnn mnonor comma Application :ua rein-nary 1a; 1930; we m. r

This invention compri'ses'improvements in or' relating te-processes and apparatus for surfacing sheet material with pigments,

varnishes, lacquers, waterproofing solutions 5 or the like. The manufacture of marbled' papers is a good illustration of the application of this invention, the expression marbled being used in a broad sense to include papers with ornamental coatings,

either monochrome .or multicolour, not only in forms or patterns which are more or lessimitative of marbles, but also in forms, such as waves,-washes'iifitripes, whichmeyll more or less irregular and may sometimes be 16 substantially uniform. In the known hand process of marbling paper, colour is deposited in a tank or tray on the surface of a-liquid medium (e. g. asolution of carra heen moss) upon which it will float, an spreading 20 naturally over the whole of that surface the colour forms a thin cohesive film. Moreor less irregular patterns may be produced in the film by stirring, and thereafter, on application of a sheet of paper to the surface of the liquid, the film adheres to the paper and is removed from the-liquidmedium on removal of the sheet. I

The above process is applicable' only to the marbling of single sheets, a sheet at a time, and it will beunderstood that after .the removal of the film anew film must be formed on the surface of the flotation liquid. With certain colours and certain flotation media it is possiblefrom a-single film to coat two 85 or even three or four sheets, but the coatings on thesubsequent sheets are thinner than and inferior to that on the first sheet. In any case this hand marbling process is necessarily laborious and costly. I 40' One object of the present invention is to provide an improved and inexpensive process which can be carried out mechanically and continuously for the reduction of ornamented sheet material: such as marbled paper, in continuous lengths, or in a succes- 4as, ias,vanaiii Great Britain rem-nar 1:, 1m.

.Sion of single sheets, 'givin effects such as have previously been referre to as marbled effects as well as coatings of colour which may be flat or almost flat. I This invention is based on thefact that films produced by the deposition on a flotation medium of suitable liquid compositions have suflicient tensile strength to enable them to be drawn alongthe surface of-the flotation liquid without disru tion. a

The suitable liqui composition may comprise pigmentsin vehicles or media, such as boiled linseed oil, and/or cellul'osic solutions (e. g. asolutioii of a cellulose esteror ether).

The composition ma also includethinning agents and/or volat' e-solvents. Insteadof 1 or in addition to pigments, the composition j may comprise varnishes,

proofing solutions and dyes The process according 'to this invention comprises the step of traversing a film-receiving surface past a fixed station over a tray, I trough or the like containing the liquid medium on which the'film is carried, insuch manner that successiveportions in the; length 10 of the film-receiving surface come into contact with'the liquid at the station andrem'ove the film by drawing it along'the surface of the liquid to thestation while the body-of the liquid remains substantially stationary. 7 It has hitherto been propose (see for example British specificationNo. 130,883) to carry out mechanically a marblingprocess by traversing a continuous web of aper over the surface of amarbling liqu' contained 'in a trough in such manner that successive portions in the length of the web come into contact with the li uidat successive points along the length 0 the trough. Insuch a process, which necessitates complicated a '86 ggriatus '(e'. g. an annular trou h rotatab e ilyor a .web c'arrying cylin er movable- 4 bodily. round the trough), the pi exitis picked u by what is in effect :1 r0 ing motion of the receiving surfacein relation tof'ac lacquers,- water- 5 is also obtained in. another known process in which, e. g. b creating a current in the floatation liquid, t at liquid is moved bodily with the film on it up to a station at which the film is taken off by thepaper. The process according upon-a dlfierent effect, namely, the drawing of a film along the surface of the flotation medium, the body of the latter remaining substantially stationary.

One example of apparatus which may be employed in the carrying out of this invention will now be described with reference to the accompanying drawings (to some. extent dia rammatic) in whichigure 1 is. a side. elevation of the machine taken at the line -11 in Fi re 2.

Figure 2 is a (shortened) $11 'of the machine shown in Fi re 1, and

Figure 3 is an en elevation of the machine. J

Like reference numerals indicate'like parts throughout the .figures. I

In the apparatus illu trated the film is formed on the surface of a liquid flotationmedium contained in a tray 10. The paper 11 to be coated is mounted on a reel 12 supfpassing in'der the ported above the tray. From this reel the paper is drawn off and passed over a guide roller 13 and then under a doctor 14 which d'i s into-the liquid in the tray 10 to a depth 0 about .a'quarter of an inc 'In this example the doctor is a flat blade; other cases be constit u' blade 14 taken. over a guide roller 15 and is then wound'on toa reel 16. The blade 14 is located near theback of the tray 10 while near the front thereof the paint or other film-forming material .is deposited on the flotation medium from pots or drospers 17 mounted on abar18. Each of the roppers 17 (of which any desired number may be rovided has a tapered nozzle the outlet .it may mm which is controlledby a needle valve 39 adjustable at. will. The .droppers 17 are adjustable settings. the blade agitator comprisin Betweenthe dropper bar 18 and 14 there is located a mechanical a shaft 19 on which is mounted a series 0 inclined discs 20 so arran ed that adjacent discs are at 'opposite inclinations to the axis of the shaft. The shaft 19 is continuously rotated by a chain drive 21 from a power-driven shaft 22 on mounted. The dropper bar 18 is continuously reciprocated, in a direction transverse to the travel of the paper, by means of a crank 23 and connectmg rod 24,the crank being on a shaft 25 ear driven from a ower shaft 26.

v n the operation 0 this apparatus, the paint or like film-forming liquid is supplied continuously at the front of the tray 10, and

to the present invention depends fer the paper is along the bar 18 to any desired at the back of the tray the paper web is continuously traversed through the flotation medium. The liquid delivered from the droppers 17 spreads out naturally over the surface of the flotation medium and forms tray, the film is agitated by the discs 20 which I produce a-wave-form effect. It will be seen therefore that in the operation of this apparatus there is a continuous formation of film which is drawn off along the surface of the flotation medium on to the paper web, with substantially no agitation of the bodyof the medium.

The movement of the web may exert a certain slight draggingaction on the floatation medium and thismay tend to set up return currents which may interfere with the forma- '-tion and distribution of the film. In'order vto avoid this difficulty a still pool may be formed in the tray 10 by immersing to a slight depth in the flotation medium an open frame 2 about the same width as the blade or doctor 14 and it is of such dimensions that a space is left between the sides of the frame and the adjacent sides of the tray. The paint isdropped into the pool enclosed by the frame, andthe space outside the frame allows the flotation medium'to recover its level, after the slight displacement caused by the dragging As shown in Figure 2 this frame is of action of the paper, without setting up return currents within the pool;

If desired the agitator shaft 19 in addition to or instead of being rotated, may have imparted to it a reciprocating motion by means of an eccentric 28 on the shaft 26 and a coupling rod 29. The reciprocation of the shaft 19 will not usually be required where the agitators take the form of oblique discs such as 20, but with other forms of agitator reciprocation of the shaft may be desirable. It will be appreciated also that in some cases the agitator may be completely omitted from the apparatus, thus allowing the film to follow its'natural course. Alternately a fixed comb or like device, through or past which the film will be drawn, maybe-provided instead of or in addition to the agitator.

In an alternative'form (not illustrated) the n lab perated.(e. by cams) to regulate the delivery of the paint. Y

The patterns which are produced on the web 11 by the operation of the ap aratus depend upona number of different actors, for

example the nature, and movement, if any, of

the paint distributing devices, the distance between the paint distributors and the doctor I 14, the particular form of agitator employed and the s eed of the motion which is imparted to 1t, and also-the speed at which the aper is run through the machine. As will e appreciated difl'erent combinations of these A factors producean indefinite number of different patterns. Straight and uniformly striped patterns may be produced by droppin the colours into parallel compartments lea ing up to the doctor 14 or equivalent device, and these compartments may for ex ample be formed by strings, strips or the like stretched across the tray '10so that they are With the apparatus illustrated herein the supply of the'paint and the a itation of the film to form patterns is carrie out to a large extent mechanically. It is to be understood that either or both of these operations may be effected by hand,-and in some casese. g.

in the imitation of fine marbles, it may be preferable to adopt the hand method.

In carrying out the process according to this invention the following, film-forming materials have been used successfully ,(a)

with petrol and (0} printers ink diluted with petrol (b) Reeves waterproof. poster colours similarly diluted ed with thinners.

acteristics. They should, when properly diluted, .form' fairly thick drops which will not sink but will spread out guickly inafilm. They must not-mix with the and finally. they should be such that they will readily adhere to the surface of the article to v be coated.

In the knownhand process for the preparation of marbled papers, ox-gall and sprinkling water are used (a) to make float better and (b) to make blobs in the film. These materials may also be employed in carrying out the-process accordin to the present invention. Films of irregu ar patterns may be produced by depositingthe colour on the flotation medium with a spray or by spraying ox-gall, wateror other liquids upon the colour.

I The flotationme'dium' upon which the film is formed ma be an aqueous solution of carraghe'enmoss, or in.many-cases plain water .may be used.

Accordingtto a further feature of this incellulose lacquers dilut-- 11 general the film-forming materials should have the following charotation medium.

vention portions of the sheet to be eoated are treated with a resist, prior to the coating operation, so as to prevent the deposition of the film on said portions. The resist may be constituted by any material which will 'pre-' vent adhesion of thefilm to the surface'of the sheet. In working with certain pigments water and a sugar solution, have been used successfully as resists. It is within the inventionto apply a resist of such a nature that it will not entirely prevent the pickin up of film by the treated portions, but

wi 1 only modify the amount of film applied.

In other words an imperfect resist maybe 'used. The resist may be'applied in any convenient way, for example by means of a roll-- er having axpattern in relief, or by spraying througha stencil. The resist may be printed in inkas a design on the paper, the

latter being traversed through the film carry -ingm'edium while the ink is still wet.

The invention is applicable not only to the coating of paper but also to the treat-. mentof textile material and sheet material generally. In treating textile material. the

a time to grippers on a cylinder which rotates in contact with the marblin liquid, or

the sheets may be carried by en less band's or the like which are traversed over the surface of the li uid.. While it is preferable that the filni' shou d be applied direct to the surface of the paper or other sheet material, it is within the invention to employ a film trans- *fer roller or other intermediate film-receiving surface, whieh takes off the film from the flotation medium and transfers it to the paper or other material togbe treated;

The apparatus described herein may be modified in many ways. For example, two webs of paper may be simultaneously marbled from one tray' by. having pigment supply means at opposite ends of the tray and by drawing ofi' two films at the centre of the tray. n Similarly, both sides of a web may be marbled by traversing opposite sides of the web through different trays. Again, a web marbled in one tray maybe conducted. to another where it will receive a coating of a difierent pigment. I

In the appended claims inwhich is recited;

a stationary flotation medium, or the equivalent thereof, such limitation is not to be construed as precluding a local agitation of the color film on the surface of thejmedium or its movement therealong.

'I claim. 1. A method.

taining the liquid su and traversing a film-receiving surface past 2. A method of coating paper including the steps of supplying coating fluid to a flotation medium to form a coating film on the surface thereof, maintaining the body of the medium substantially stationary, and removing the film from the medium by traversing a paper sheet past a fixed point adjacent the liquid surface to pick up the film and draw additional coating material toward said point over the surface of the stationary flotation medium.

3. A method of coating paper including.

the steps of supplying film-forming fluid to a stationary body of a flotation medium, and removing the film from the mediumby continuously bringing paper into engagement with the film at a'fixed point to cause adherence of the latter to the former for stripping it from the medium and movingthe film across the surface of the medium by its own surface tension.

4. A method of coating sheet material including the steps of forming a coating film on the-surface of a bodgsqf liquid while maina fixed point near the surface of the liquid I to cause adherence of the film to the receiving surface and movement of the film over the surface of the li uid.

5. A method of coating including the steps of suppl ing film-forming liquid to a stationary otation medium at one station on the surface thereof, and picking up said film and drawing it along said surface by causing a continuous web to engage the film at another fixed station on said surface.

6. In amethod of coating, the steps including supplying a film-forming fluid'to a stationary flotation medium, and drawing the film along the surface of the medium and stripping. it therefrom by traversing a continuous web past a fixed point, in engagement with the film. i

7. A process according to claim 6 including the additional step of treating portions of the web with a resist prior to the'coating opertantially stationary,

along the surface of the flotation medium, to form a pattern on the film.

9. A procem accordin to claim 6 includ-) ing the additional step 0 depositin the filmforming fluid on the flotation m mm 50 as to make a patterned film..

10. A process according to claim 6 includ ing .the additional step of confining the deposition of the film-formin fluid to ortions of said medium spaced. rom the gas thereof.

In testimon whereof I aflix in Si ature.

GEOB E MAoKENZTE R WN.

ation,'to prevent deposition of film on said portions.

8.- A-process as claimed in claim 6 including the additional step of effecting local agitation in thefilm while the-latter is being drawn us i 

